The overall objective of the proposed research is to develop efficient methodology for the total synthesis of the anticancer terpenoids taxodione, bruceantin, and analogs thereof. A Diels-Alder strategy is to be employed in the bruceantin synthesis which will firmly establsh proper stereochemical relationships in at least four of the five rings. Intermediates and analogs will be submitted to NCI as they become available for screening. A Diels-Alder strategy is also proposed for taxodione together with a novel benzocyclobutenone opening.